+use super::pat::Expected;
use super::ty::AllowPlus;
-use super::TokenType;
-use super::{BlockMode, Parser, PathStyle, Restrictions, SemiColonMode, SeqSep, TokenExpectType};
+use super::{
+ BlockMode, Parser, PathStyle, RecoverColon, RecoverComma, Restrictions, SemiColonMode, SeqSep,
+ TokenExpectType, TokenType,
+};
use rustc_ast as ast;
use rustc_ast::ptr::P;
use rustc_span::symbol::{kw, Ident};
use rustc_span::{MultiSpan, Span, SpanSnippetError, DUMMY_SP};
+use std::mem::take;
+
use tracing::{debug, trace};
const TURBOFISH_SUGGESTION_STR: &str =
}
}
- let expect = tokens_to_string(&expected[..]);
+ let expect = tokens_to_string(&expected);
let actual = super::token_descr(&self.token);
let (msg_exp, (label_sp, label_exp)) = if expected.len() > 1 {
let short_expect = if expected.len() > 6 {
// So far we have parsed `foo<bar<`, consume the rest of the type args.
let modifiers =
[(token::Lt, 1), (token::Gt, -1), (token::BinOp(token::Shr), -2)];
- self.consume_tts(1, &modifiers[..]);
+ self.consume_tts(1, &modifiers);
if !&[token::OpenDelim(token::Paren), token::ModSep]
.contains(&self.token.kind)
// Consume the fn call arguments.
let modifiers =
[(token::OpenDelim(token::Paren), 1), (token::CloseDelim(token::Paren), -1)];
- self.consume_tts(1, &modifiers[..]);
+ self.consume_tts(1, &modifiers);
if self.token.kind == token::Eof {
// Not entirely sure that what we consumed were fn arguments, rollback.
}
pub fn maybe_consume_incorrect_semicolon(&mut self, items: &[P<Item>]) -> bool {
- if self.eat(&token::Semi) {
+ if self.token.kind == TokenKind::Semi {
+ self.bump();
let mut err = self.struct_span_err(self.prev_token.span, "expected item, found `;`");
err.span_suggestion_short(
self.prev_token.span,
);
err
}
+
+ /// Some special error handling for the "top-level" patterns in a match arm,
+ /// `for` loop, `let`, &c. (in contrast to subpatterns within such).
+ crate fn maybe_recover_colon_colon_in_pat_typo(
+ &mut self,
+ mut first_pat: P<Pat>,
+ ra: RecoverColon,
+ expected: Expected,
+ ) -> P<Pat> {
+ if RecoverColon::Yes != ra || token::Colon != self.token.kind {
+ return first_pat;
+ }
+ if !matches!(first_pat.kind, PatKind::Ident(_, _, None) | PatKind::Path(..))
+ || !self.look_ahead(1, |token| token.is_ident() && !token.is_reserved_ident())
+ {
+ return first_pat;
+ }
+ // The pattern looks like it might be a path with a `::` -> `:` typo:
+ // `match foo { bar:baz => {} }`
+ let span = self.token.span;
+ // We only emit "unexpected `:`" error here if we can successfully parse the
+ // whole pattern correctly in that case.
+ let snapshot = self.clone();
+
+ // Create error for "unexpected `:`".
+ match self.expected_one_of_not_found(&[], &[]) {
+ Err(mut err) => {
+ self.bump(); // Skip the `:`.
+ match self.parse_pat_no_top_alt(expected) {
+ Err(mut inner_err) => {
+ // Carry on as if we had not done anything, callers will emit a
+ // reasonable error.
+ inner_err.cancel();
+ err.cancel();
+ *self = snapshot;
+ }
+ Ok(mut pat) => {
+ // We've parsed the rest of the pattern.
+ let new_span = first_pat.span.to(pat.span);
+ let mut show_sugg = false;
+ // Try to construct a recovered pattern.
+ match &mut pat.kind {
+ PatKind::Struct(qself @ None, path, ..)
+ | PatKind::TupleStruct(qself @ None, path, _)
+ | PatKind::Path(qself @ None, path) => match &first_pat.kind {
+ PatKind::Ident(_, ident, _) => {
+ path.segments.insert(0, PathSegment::from_ident(ident.clone()));
+ path.span = new_span;
+ show_sugg = true;
+ first_pat = pat;
+ }
+ PatKind::Path(old_qself, old_path) => {
+ path.segments = old_path
+ .segments
+ .iter()
+ .cloned()
+ .chain(take(&mut path.segments))
+ .collect();
+ path.span = new_span;
+ *qself = old_qself.clone();
+ first_pat = pat;
+ show_sugg = true;
+ }
+ _ => {}
+ },
+ PatKind::Ident(BindingMode::ByValue(Mutability::Not), ident, None) => {
+ match &first_pat.kind {
+ PatKind::Ident(_, old_ident, _) => {
+ let path = PatKind::Path(
+ None,
+ Path {
+ span: new_span,
+ segments: vec![
+ PathSegment::from_ident(old_ident.clone()),
+ PathSegment::from_ident(ident.clone()),
+ ],
+ tokens: None,
+ },
+ );
+ first_pat = self.mk_pat(new_span, path);
+ show_sugg = true;
+ }
+ PatKind::Path(old_qself, old_path) => {
+ let mut segments = old_path.segments.clone();
+ segments.push(PathSegment::from_ident(ident.clone()));
+ let path = PatKind::Path(
+ old_qself.clone(),
+ Path { span: new_span, segments, tokens: None },
+ );
+ first_pat = self.mk_pat(new_span, path);
+ show_sugg = true;
+ }
+ _ => {}
+ }
+ }
+ _ => {}
+ }
+ if show_sugg {
+ err.span_suggestion(
+ span,
+ "maybe write a path separator here",
+ "::".to_string(),
+ Applicability::MaybeIncorrect,
+ );
+ } else {
+ first_pat = self.mk_pat(new_span, PatKind::Wild);
+ }
+ err.emit();
+ }
+ }
+ }
+ _ => {
+ // Carry on as if we had not done anything. This should be unreachable.
+ *self = snapshot;
+ }
+ };
+ first_pat
+ }
+
+ /// Some special error handling for the "top-level" patterns in a match arm,
+ /// `for` loop, `let`, &c. (in contrast to subpatterns within such).
+ crate fn maybe_recover_unexpected_comma(
+ &mut self,
+ lo: Span,
+ rc: RecoverComma,
+ ) -> PResult<'a, ()> {
+ if rc == RecoverComma::No || self.token != token::Comma {
+ return Ok(());
+ }
+
+ // An unexpected comma after a top-level pattern is a clue that the
+ // user (perhaps more accustomed to some other language) forgot the
+ // parentheses in what should have been a tuple pattern; return a
+ // suggestion-enhanced error here rather than choking on the comma later.
+ let comma_span = self.token.span;
+ self.bump();
+ if let Err(mut err) = self.skip_pat_list() {
+ // We didn't expect this to work anyway; we just wanted to advance to the
+ // end of the comma-sequence so we know the span to suggest parenthesizing.
+ err.cancel();
+ }
+ let seq_span = lo.to(self.prev_token.span);
+ let mut err = self.struct_span_err(comma_span, "unexpected `,` in pattern");
+ if let Ok(seq_snippet) = self.span_to_snippet(seq_span) {
+ const MSG: &str = "try adding parentheses to match on a tuple...";
+
+ err.span_suggestion(
+ seq_span,
+ MSG,
+ format!("({})", seq_snippet),
+ Applicability::MachineApplicable,
+ );
+ err.span_suggestion(
+ seq_span,
+ "...or a vertical bar to match on multiple alternatives",
+ seq_snippet.replace(',', " |"),
+ Applicability::MachineApplicable,
+ );
+ }
+ Err(err)
+ }
+
+ /// Parse and throw away a parenthesized comma separated
+ /// sequence of patterns until `)` is reached.
+ fn skip_pat_list(&mut self) -> PResult<'a, ()> {
+ while !self.check(&token::CloseDelim(token::Paren)) {
+ self.parse_pat_no_top_alt(None)?;
+ if !self.eat(&token::Comma) {
+ return Ok(());
+ }
+ }
+ Ok(())
+ }
}
projects / rustc.git / blobdiff